1. Field of the Invention
The present invention relates to an organic electroluminescent device and fabrication methods thereof, and more particularly to compensation of an organic electroluminescent device.
2. Description of the Related Art
Organic electroluminescent devices are also known as organic light emitting diodes (OLED). A voltage is applied to an organic molecular material or polymer material to cause a device to emit light. Due to self emission characteristics of an OLED, dot matrix type displays with light weight, slim profile, high contrast, low power consumption, high resolution, fast response time, no backlight, and wide viewing angle can be achieved. Possible display parameters ranging from 4 mm micro-displays to 100 inch outdoor billboards make them a preferred light source for flat panel displays (FPD). If luminescent efficiency of the OLEDs is over 100 Lm/W, they can replace conventional lighting.
As shown in FIG. 1, an organic electroluminescent device is operated by a switch transistor 102, and a driving transistor 104 coupling to a power line Vp. Organic electroluminescent devices 106, however, suffer from non-uniform brightness between pixels. Specifically brightness of the organic electroluminescent device 106 decays with long term use.